Formula 1000 Race Car Blog

Category Archives: Grinding

Here’s a big project that spread out over a number of months. I’m aggregated the photos here and attempted to make them tell a coherent story.

The cluster as a whole can be adjusted forward and back for drivers of different heights. The gas pedal is adjustable for foot travel, throttle cable travel and left/right position. The brake pedal height is independently adjustable, and brake bias is adjustable from front to back. The hydraulic clutch pedal is also independently adjustable for height.

Many of the original pieces were laser cut from steel, then bent and welded to form the complex shapes required. Some of the bushings were CNC turned, but most were made by hand. The master cylinders, brake bias adjustment cable, and the nuts and bolts were purchased, with everything else custom made. This includes the brake bias adjustment assembly, which forced me to learn how to cut threads on the lathe. It’s not as easy as it looks. Take a look at the brake bias adjustment bar– it has three sets of threads independently cut on a manual lathe, three diameters, two snap rings and a threaded hole. Good fun! Due to changes in the steering rack mount, the main pedal bracket had to be widened as you can see in the photos.

The car will use standard Honda Civic axle halfshafts, and I had the choice of cutting, sleeving and re-welding them, or building extenders that effectively widen the differential to meet the unmodified halfshafts. The cut/sleeve/re-weld option would eliminate the axle hardening and leave unknown strength, and I’ve since seen an example where this was done and the axle broke right at the weld. The option of “widening” the differential has several advantages. First, we can easily replace the halfshafts if necessary in the future with off-the-shelf parts. Second, moving the inner constant-velocity joint closer to the plane of the control-arm pickup points minimizes the plunge, or change in length, required as the suspension moves through its travel. Third, the halfshafts become equal length, eliminating torque steer. Now you may say “but, the extensions will be of different length and will twist unevenly so the torque steer won’t be eliminated”. The extensions will be much stiffer than the axle shafts so that won’t be the case.

So the choice was clear. We started with a differential and a couple of halfshafts as raw material…